Valve structure for pneumatic tires having dual tubes



Aug. 26, 1952 E. T. WYMAN 2,608,235

VALVE STRUCTURE FOR PNEUMATIC TIRES HAVING DUAL TUBES Filed Jan. s1, 195o 2 sl-lEETsf-sl-IEET 1 E. T. WYM AN Aug. 26., 1952 VALVE STRUCTURE FOR PNEUMATIC TIRES HAVING DUAL TUBES 2' sHEETs-smET- 2 Filed Jan. 3l, 1950 Patented Aug. 26,1952

*UNITED STATE s PATENT OFFICE VALVE STRUCTURE FORPNEUMATIC 'rIRES i HAVING DUAL TUBES l y Edwin T Wyman, Brookline, Mass. Application January 31, 1950, Serial No. 141.502

clams.' (c1. 152-7340) inner and. -outer vair chambers (of the lsafety tube, and tire casing, respectively) and the Ino-4 torist can readily test at any time the exact amount of air pressure in each chamber. j

Before explaining in detail the presentinvention, it is to be understood that the invention is not 'limited in its application to the details'of construction and arrangement of partsglllustrated in the accompanying drawings, since the inyen-I For that situation I have devised .a single valve structure whereby both tubes may be separately inated. Because there is'no inter-communication between the tWo tubes, it will be understood that should the other inflatable tube become deflated through a puncture, blow-out or for other cause, the auxiliary or safety tubev Will support the vehicle indefinitelyv and independently of the collapsed outer air chamber, which may be the so-called standard .inner tube, or the so-called "tubeless tire casing. For such a valve structure to be practical, howevenit is of the utmost importance that it be simple and inexpensiveto manufacture and to instalLbe efficient in operation, and relativelyleakeproof. The previous valve ystructures with which I have been familiar, and which have been used for inflating dual` tubes or tires as .above described haveall been robjectionable or impractical for one or .more reasons, and do not obtain as completely the .results and advantages achieved by my present valve structure. The complicated mechanism inside the valve stemvand the leakage of air from the stem, as in valves where the stem is screwed'down to close yone of the air passages, is eliminated.

`Briefly my Avalvevstructure Acomprises a single .main valve stem having tWo standard separate air valves 4operating through two. separate air passages', by which the .safety tube and tire lcasing 'are separately inflated. The valve stem is 'vulcani-Zed 'at its base at proper position inthe sideifol'f the auxiliary or safety tube, the base carrying a part, through which the latter tube .is inftated.A A detachable branching valve stem .secured to the maincstem 'carries the second valve, .by which, through a separate air passage, the tire casing is in'ated. The detachable valve vstein the safety tube to be readily "installed -on the rirh inside the outer vair chamber.` With my I'valvestructure there is' 'thus no possibility"bi bom-nunication between: the

tion `is capable of A'other embodiments and. fof being practiced or carried' out in various Ways.` Also it is to be understood that thephraseology or terminology employed herein is for the purpose of description and not of limitation. and it is not intended to vlimit the invention claimed 'herein beyond they requirements of the prior art.

' l In thedravvings:

Fig. l'is a side elevation showing my valve structure as mounted in a tubeless safetyl'tir'e'; Fig. `2 is an enlarged longitudinalsectional view ofthe samevalve on lines 2-/2 of Fig. 1 Fig. 3 is a horizontal section on line 3 3 of Fig.2; Y Fig. 4 is a side elevation of the tube shown in j l'ig.V 1V ,but adapted to ay diierent type of safety tubej-and f 'i Fig. 5 is a side elevation of the valve structure as used in another modified form or safety tube. VIt will be understood thatV my valve .structure is designed particularly to be used in a tubeless safety tire. I e, My valve structure, however,v is obviously not limited thereto, but'it is adapted to be used in vany type of pneumatic tire having dual inilated air chambers, Vone being the ordinary outer airfchamber `of either. the standard-inner tube type,.or the tubeless type previously mentioned, and, the second being the auxiliary safety tube which supports the vehicle independently when the outer air chamber collapses because of ay blowout, puncture or the like. p y j f In the drawings I0 represents :a standard rubber vtire casing having a tread portion I I with grooves I2 formed in the tread portion and having side walls I3 and beaded edges I4." It Wll'be understood that'the beaded edge I4 is usually stifen'e'd and strengthened Withzannular Wire strands (not shown) which run around'ft'he tire insidethe beaded edge I4. A lining vor thick coating I6 of Va self-sealing'plastic ycompound 'of :any suitable nature is provided on the interior 'of `the .tire I0 beneath its 'tread surface, which isdesi'gned to seal punctures and holes `"caused by n'ails fand other' objects piercing `the tread surface. A rubber lining is preferably provided on the interior of the tire casing I and over the coating I to prevent diffusion of air into the walls of the tire and possible separation of the fabric cords therein from the surrounding rubber material.

The standard tire casing I0 thus described is adaptedto be mounted on a standard wheelk rim which, as shown in the drawings (Figs. 1, 4, and 5), is of the standard drop-center type having the drop-center portion 2| comprising the bottom wall 2|a, side walls 2lb, and angular recesses 22 at the sides thereof, comprising bottomI wall 22a and side Wall 22h, into which the angular outer surface of the beaded edges |.4 of the tire Ill are designed to nt.

A separate pair of annular bands of rubber 25 may be provided as shown, preferably having two preformed angularly disposed parts or surfaces 25a and 25b, which bands are designed to fit into the angular recesses 22 at the sides of the rim 20, and between the tire and the rim, and to receive the angular edge of the beads I4 of the tire casing I0 (as shown in Figs. l, 4 and 5).

An auxiliary or safety tube 4|] of rubber, entif-ely separate from the tire casing l0, is provided to be inserted within the tire casing |0 and closely hug, when inflated, the drop-.center portion `2| of therim 20, as'shown inFig. 1.

The safety tube of Fig. 1 comprises the outer n Wall 42, preferably inextensible in nature, and formed of'two or more layers of cord or Woven fabric 42a and oneor more layers of rubber 42h suitably arranged. 'An inner base wall or belly '44 formed of stretchable material such as sheet rubber isk vulcanized to the outer wall 42 at its adjoining edges adjacent the bead engaging zone of the tube 4U. As shown inFig. 1, it will be noted that the bottom wall 44 is extended on inflation to engage the inner drop-center portion 2| of the rim 20. Means is provided to permit passage of air around the sides of safety tube 40 into the outer chamber a of the tire casing I0 which inthe form shown in Fig. 1 comprises Yan annular row of spaced ridges 5B with grooves therebetween constituting air passages into the outer chamber a of tire casing IU, In Fig. 5 a modified form of communicating air passage is shown.

jAs shownin Figsl, 2, 3, 4 and 5, my valve structure comprises a single valve stem 60 having a central longitudinal air passage 6| therethrough which leads into the safety tube. A standardgvalve member B4 is Acarried into the central'air passage 6|, but as this is a standard construction, it needrnot be described in detail. A separate detachable branching valve stem 65 is provided, to be inserted into the side of main valve stem 60 by means of a threaded base 'I3 in a cooperating threaded aperture therefor, and is maintained therein by means of threaded lock nut 68. Detachable valve stem 65 again carries a central air passage 66 with standard valve member 61 inserted therein. Central air passage |56 leads into air passage 68 provided in main valve stem BD parallel to central air passage 6| but not in communication therewith. As s hown in Figs. 2 and 3, air passage 68 surrounds air passage 6|. Air passage 68 then ex- 'tends laterally at 68a through the flanged base 62 of thev main valve structure 60, to communicate with the space or outer chamber a of the tire casing 0. It will thus be seen that branching valve stem 66 with air passage 68 and 68a is the means for infiating the tire casing IU sep- 4 arately and apart from the safety tube 40 or B0.

Means is provided for clamping the valve structure to the side wall 2lb of the rim 20, which includes the base fiange 62 integral with the valve stem 60. Such means includes a rubber washer 10, the retaining ring or Washer 1|, and the threaded nut 12. It will be noted (Fig. 2) that the side wall 2lb Aof the.. rim 20 is held securely clamped betweenthe rubber Washer 10 and retaining ring 1|, which are tightly clamped together by means of threaded nut 12. If desired, an additional rubber washer may be interposed on the outside of the side wall 2lb of the rim. As seen in Fig. 3, two longitudinal sides of the valve stem 60 are preferably fiat and parallel, so that the branching valve stem 65 may be mounted on the valve stern 60 and secured by means of lock nut 69.

In use, the safety tube 40 is first placed inside the tire casing IU and both are mounted on the rim 20 in the conventional manner. The valve stem 60, being vulcanized in proper position on the side of safety tube 40, with branching valve stem 65 detached therefrom, is then inserted through a suitable aperture provided therefor in side wall 2 lb of the rim 20. The annular rubber bands 25 are then stretched and placed in position in the angular recess 22 of the rim 20 between the beaded edge I4 of .the tire casing l0, and the recess 22'of the rim 20. Thebands 25 being in place, andthe branching valve stem 65 being inserted in the side of main valvestem 6D, and the nut G9 being screwed thereon, the safety tube 40 is inflated through main valve stem 60 and central air passage El, and port 53 which communicates directly with the interior of the safety tube 48. The tire casing I0 is inflated through the branching valve stem 65. It will be remembered that the air proceeds through air passage 68 and its lateral extension 68a, through the air passages provided at the sides of the safety tube 40 between the spaced ridges 5U, and thence into the chamber a of the tire casing l0. It will be noted that air pressure within the outer chamber a of the tire casing I0 and within the safety tube '40 forces thevbeaded edges I4 of the tire casing I0 tightly against the annular rubber bands interposed between said beaded edges and the angular recess 22 of the rim 20 to form an airtight seal. There being no air communication between safety tube and the outer chamber -a of tire casing I0, safety tube 40 will at all times provide an auxiliary safety support for the tire l0. in the event of deflation of the latter through puncture, blow-out or other injury.

In Fig. 4. I have shown a modification of safety tube 80, composed throughout its circumference of inextensible material such as with two or more layers of cord or woven fabric 8| a and one or more layers h of rubber suitably arranged. The toroidalshaped safety tube 80 is thus substantially circular in shape in crosssection shown in Fig. 4, and the belly or lower portion 8|, does not extend into the recess of the drop center 2| of the rim 20. Suitable air passages between safety tube 80 and the inner .walls of tire casing l0 are provided, as by means of an annular row of grooves 5| therebetween, as on the first form of safety tube 40. The valve structure is the same as that shown in Figs. 1, 2 and 3, with the exception that the main valve stem is vulcanized to an extended tubular neck 82 extending from the ,lower or belly portion 8| of the safety tube 80.

eral extension (not shown) similar to lill may.

be provided, extending into the drop-center 2i of the rim to further vent air to the chamber a between the safety tube 49 and the' tire casing I6. Such an additional lateral extension would be particularly useful with respect to the type of safety tube construction shown in Fig. 4.

-My invention is not limited to the precise constructions shown herein but may be modified in many details, without departure from the spirit of the invention and within the scope of the claims.

It will, of course, be understood that the term rubber as used herein indicates both natural and synthetic rubber and substances having rubber-like properties and characteristics as full equivalents.

In the appended claims, the term outer tube refers to the inner tube of the standard tire assembly, or the tire casing of the so-called tubeless tire, and the term auxiliary tube or safety tube refers to the second tube carried within the first tube for emergency support of the vehicle in the event of puncture or blow-out of the Outer tube.

I claim:

1. A unitary valve structure for use in inflating pneumatic tires comprising two separate air chambers as used on vehicle wheels, wherein an auxiliary safety tube is carried within an outer chamber without air communication between them, comprising a main valve stem fixed to the auxiliary tube and having an auxiliary passage with a check valve therein for inilating said auxiliary tube, a second valve stem detachably connected to the main valve stem and having an air passage and check valve therein communicating with a second air passage in the main Valve stem for inilating said outer chamber, and means for fastening said main Valve stem to a vehicle wheel rim.

2. A unitary valve structure for use in inflating pneumatic tires comprising two separate air chambers as used on vehicle wheels, wherein an auxiliary safety tube is carried within an outer chamber without air communication between them, comprising `a main valve stem xed to the auxiliary tube and having a central air passage with a check Valve therein communicating with the interior of said auxiliary tube, a second valve stem detachably connected to the main Valve stem and having an air passage and check Valve therein communicating with a second air passage in the main valve stem leading to the interior of said outer chamber, and means for fastening said main Valve stem to a vehicle wheel rim.

3. A unitary valve structure for use in inflating pneumatic tires comprising two separate air chambers as used on vehicles, wherein an auxiliary safety tube is carried within an outer chamber Without air communication between them, comprising a main valve stem xed to the auxiliary tube and having a central air passage with a check valve therein for infiating said auxiliary tube, a laterally projecting branch valve stem detachably connected to the first main valve stem and having an air passage and check valve therein communicating with a second air passage in the main valve stem for inflating said outer chamber, and means for fastening said main stem to a vehicle wheel-rim.

4. A unitary valve structure for use ininflating pneumatic tires comprising two separate air chambers as used on vehicle wheels, wherein an auxiliary safety tube is carried within an outer chamber without air communication between them, comprising a main valve stem fixed to the auxiliary tube and having a central air passage with a check valve therein communicating with the interior of said auxiliary tube, a second valvestem detachably connected to the main valve stem and having an air passage and check Valve therein communicating with a second air passage in the main valve stem surrounding the central air passage in the main valve stem leading to the interior of said outer chamber, and means for fastening said main valve stem to a vehicle wheel rim.

5. A unitary valve structure according to claim 1 in which the main valve stem has a flanged base with ports extending laterally therein connecting with said second air passage in the main valve stem for inilating said outer chamber.

EDWIN T. WYMAN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 804,613 Magowan Nov. 14,1905 1,541,725 Dunn June 9, 1925 1,626,511 Clark Apr. 26, 1927 1,650,502 Ehrler Nov. V22, 1927 1,653,054 Mack Dec. 20, 1927 2,189,485 Crowley Feb. 6, 1940 2,272,548 Creamer Feb. 10, 1942 

